EP4219580A1 - Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien - Google Patents

Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien Download PDF

Info

Publication number
EP4219580A1
EP4219580A1 EP22153603.0A EP22153603A EP4219580A1 EP 4219580 A1 EP4219580 A1 EP 4219580A1 EP 22153603 A EP22153603 A EP 22153603A EP 4219580 A1 EP4219580 A1 EP 4219580A1
Authority
EP
European Patent Office
Prior art keywords
adhesive composition
composition according
adhesive
flexible packaging
packaging material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22153603.0A
Other languages
English (en)
French (fr)
Inventor
Marcel FRANKEN
Henrik Kalmer
Pascal WILKENS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Henkel AG and Co KGaA
Original Assignee
Henkel AG and Co KGaA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Henkel AG and Co KGaA filed Critical Henkel AG and Co KGaA
Priority to EP22153603.0A priority Critical patent/EP4219580A1/de
Priority to PCT/EP2023/050038 priority patent/WO2023143876A1/en
Publication of EP4219580A1 publication Critical patent/EP4219580A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
    • C08G18/75—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic
    • C08G18/751—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring
    • C08G18/752—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group
    • C08G18/753—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group
    • C08G18/755—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B32B15/085—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B32B15/09—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/30—Low-molecular-weight compounds
    • C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
    • C08G18/3271—Hydroxyamines
    • C08G18/3275—Hydroxyamines containing two hydroxy groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40—High-molecular-weight compounds
    • C08G18/48—Polyethers
    • C08G18/4833—Polyethers containing oxyethylene units
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/7806—Nitrogen containing -N-C=0 groups
    • C08G18/7818—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups
    • C08G18/7831—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups containing biuret groups
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C09J175/08—Polyurethanes from polyethers

Definitions

  • the present invention relates to a solvent-based polyurethane adhesive composition for bonding flexible packaging materials, which is debondable by treating with water or an aqueous solution. Further, the present invention relates to method of manufacturing the flexible packaging material by using the solvent-based polyurethane adhesive composition and a method of recycling the flexible packaging materials.
  • the flexible package when filled with a food or other product and closed or sealed can be readily changed in shape.
  • the flexible package is typically prepared from two layers of flexible packaging material that are overlaid and sealed around most of their periphery to form a cavity inside.
  • the two layers of flexible packaging material are heat sealed by applying heat and pressure to fuse the layers together around a thin portion of the package periphery.
  • Food or other product is placed in the cavity through an opening and the opening is closed by heat sealing the layers together.
  • the sealed package and enclosed product can be heated for preservation purposes.
  • Flexible packaging material is prepared by laminating two or more layers of film. Each layer of the flexible packaging material is bonded to the adjacent layer by an adhesive. Adhesive can be applied to the layer from a solution in a suitable solvent using gravure or smooth roll coating cylinders or from a solvent-free state using special application machinery and that layer is laminated to another layer. The laminated packaging material is dried if necessary and accumulated in rolls. The rolls are kept in storage for a predetermined amount of time to allow the adhesive to cure before use in some applications.
  • polyurethane based adhesives are preferred for use in flexible packaging materials because of their many desirable properties including good adhesion to the materials in each layer, high bonding strength, resistance to heat such as from heat sealing or retorting, and resistance to chemically aggressive products.
  • US 6,870,006 B2 discloses a water-soluble hotmelt adhesive, containing: 40 to 70% by weight of at least one homopolymer or copolymer with free carboxylic acid groups based on ethylenically unsaturated monomers (component A), 15 to 45% by weight of at least one water-soluble or water-dispersible polyurethane (component B), 10 to 45% by weight of at least one inorganic or organic base (component C), and 0 to 20% by weight of further additives (component D), wherein the sum of such components is 100% by weight.
  • the water-soluble hotmelt adhesive is suitable for producing textile laminates, moisture-tackifiable papers and at least two-ply hygiene-papers, in particular tissue.
  • a first object of the invention is to provide a solvent-based polyurethane adhesive composition comprising,
  • Another object of the invention is to provide a flexible packaging material comprising a first layer comprised of a first polyolefin or first polyester; a second layer comprised of a second polyolefin, which may be the same or different from the first polyolefin, a second polyester, which may be the same as or different from the first polyester, or a metal foil; and cured adhesive of the adhesive composition according to the present invention bonding the first layer to the second layer.
  • Yet another object of the invention is to provide a method of recycling a flexible packaging material comprising,
  • Figure 1 shows a sectional view of a food packaging material according to the present invention.
  • a molecular weight of a polymer refers to the average number weight M n , unless stated otherwise.
  • the number average molecular weight M n of a polymer can, for example, be determined by gel permeation chromatography (GPC) according to DIN 55674 with THF as the eluent. If not stated otherwise, all given molecular weights are those determined by GPC, calibrated with polystyrene standards.
  • the average molecular weight M w can also be determined by GPC, as described for M n .
  • Atmospheric conditions refers to conditions at a temperature of 25°C and pressure of 101.325 kPa.
  • the disclosed polyurethane adhesive composition comprises
  • Polyisocyanate is used to react with isocyanate-reactive compounds to produce the polyurethane polymer for the adhesive composition according to the present invention.
  • Polyisocyanate refers to any organic compound containing two or more isocyanate groups.
  • the polyisocyanate selected from an aliphatic polyisocyanate, alicyclic polyisocyanate and combination thereof.
  • the "aliphatic polyisocyanate” means a monomer or oligomer which has a chain-like hydrocarbon chain to which an isocyanate group is directly bonded, and also has no cyclic hydrocarbon chain.
  • the "aliphatic isocyanate” may have an aromatic ring, but the isocyanate group is not bonded directly to the aromatic ring.
  • the cyclic hydrocarbon chain does not contain aromatic rings.
  • the "alicyclic polyisocyanate” means a monomer or oligomer which has a cyclic hydrocarbon chain, and may have a chain-like hydrocarbon chain.
  • the isocyanate group may be directly bonded to the cyclic hydrocarbon chain, or may be directly bonded to a chain-like hydrocarbon chain which may be present.
  • the “alicyclic polyisocyanate” may have an aromatic ring, the isocyanate group is not directly bonded to the aromatic ring.
  • 4,4'-diphenylmethane diisocyanate corresponds to the aromatic polyisocyanate, since the isocyanate group is directly bonded to the aromatic ring.
  • xylylene diisocyanate corresponds to the aliphatic polyisocyanate, although it has an aromatic ring, since the isocyanate group is not directly bonded to the aromatic ring and is bonded to the methylene group.
  • the aromatic ring may have a ring-fused structure in which two or more benzene rings are condensed.
  • aliphatic polyisocyanate examples include 1,2-ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4(2,4,4)-trimethyl-1,6-hexamethylene diisocyanate (TMDI), 1,9-diisocyanato-5-methylnonane, 1,8-diisocyanato-2,4-dimethyloctane, 1,12-dodecane diisocyanate, ⁇ , ⁇ '-diisocyanatodipropyl ether, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 1,4-diisocyanatomethyl-2,3,5,6-tetramethylcyclohexane, 2-methyl-1,5-diisocyanatopentane (MPDI), 2-ethyl-1,4-di
  • alicyclic polyisocyanate examples include 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (isophorone diisocyanate), 1,3-bis(isocyanatomethyl)cyclohexane (hydrogenated xylylene diisocyanate), bis(4-isocyanatocyclohexyl)methane (hydrogenated diphenylmethane diisocyanate), 1,4-diisocyanatocyclohexane and the oligomer thereof.
  • the aliphatic or alicyclic polyisocyanate is also preferably a compound having 3 or more isocyanate groups.
  • Such isocyanate-functionalized compound is preferably an adduct of various polyisocyanates with polyols such as 2-methylpentane-2,4-diol and trimethylolpropane, such as an adduct of diisocyanate such as HDI, XDI, and IPDI with trimethylolpropane, and a trimer having an isocyanurate ring.
  • polyisocyanate-modified product a carbodiimide group, a uretdione group, a uretonimine group, a burette group reacted with water, a group of isocyanurate groups, or a modified product having two or more of these groups can be used.
  • the polyisocyanate is selected from IPDI, HDI, XDI, their adducts, their oligomers and the mixture of above. In a more preferred embodiment, the polyisocyanate is selected from IPDI, HDI, their oligomers and combination thereof. In a most preferred embodiment, the polyisocyanate is IPDI commercially available from e.g. Sigma Aldrich.
  • the polyisocyanate is present in the reactants of polyurethane polymer from 10 to 60 wt.%, preferably 20 to 50 wt.%, based on the total weight of the reactants of the polyurethane polymer.
  • the reactants may comprise other polyisocyanates such as aromatic polyisocyanates if excellent adhesion strength and debonding effect of the adhesive still can be achieved.
  • the reactants essentially comprise no aromatic polyisocyanates, such as MDI.
  • the reactants, based on the total weight of the reactants comprise less than 25% by weight of, or less than 10% by weight of, or less than 5% by weight of, or less than 1% by weight of, or comprise no aromatic polyisocyanates, such as MDI.
  • the selected polyisocyanate reacts with a mixture of isocyanate-reactive compounds.
  • the mixture of isocyanate-reactive compounds comprises a polyether polyol.
  • the polyether polyol is preferably a polyether diol which comprises primary hydroxyl groups or a mixture of primary and secondary hydroxyl groups.
  • suitable polyether polyols are polyoxyalkylene polyols such as polyethylene glycol, polypropylene glycol, polytetramethyl glycol and polybutyl glycol. Also, homopolymers or copolymers of the listed polyoxyalkylene polyols as well as mixtures thereof are suitable for the purpose of the present invention.
  • Particularly suitable copolymers are those comprising an adduct of a compound selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, propylene glycol, triethylene glycol, 2-ethylhexandiol-1,3-glycerine, trimethylolpropane, trimethylolethane, tris(hydroxyphenyl)propane, triethanolamine and triisopropylamine with at least one compound selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide.
  • the polyether polyol is selected from polyethylene glycol, polypropylene glycol, polytetramethyl glycol, polybutyl glycol, and combination thereof, and preferably is polyethylene glycol.
  • the polyether polyol may have a number averaged molecular weight from larger than 200 to less than 1000. If the molecular weight of the polyether polyol is lower or higher than the above range, the speed of reaction with polyisocyanate will be significantly slower.
  • the polyether polyol has a number averaged molecular weight (Mn) from 250 to 950 g/mol, and preferably from 300 to 800 g/mol.
  • Mn number averaged molecular weight
  • the polyisocyanate is present in the reactants of polyurethane polymer from 10 to 60 wt.%, preferably 15 to 50 wt.%, based on the total weight of the reactants of the polyurethane polymer.
  • the mixture of isocyanate-reactive compounds further comprises an amine represented by Formula (1) wherein R 1 is C 1-3 alkyl, such as methyl, ethyl, propyl, Y is hydrogen, Z is C 1-3 alkyl or hydrogen, a is an integer of 1 to 5, and b is an integer of 0 to 5.
  • R 1 is C 1-3 alkyl, such as methyl, ethyl, propyl
  • Y is hydrogen
  • Z is C 1-3 alkyl or hydrogen
  • a is an integer of 1 to 5
  • b is an integer of 0 to 5.
  • R 1 Z, a is 1, and b is 0.
  • Z is hydrogen, a is 1 and b is 1.
  • the amine of Formula (1) is selected from N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dipropylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, and combination thereof, preferably is selected from N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, and combination thereof, and more preferably is N-methyldiethanolamine, commercially available from e.g. Sigma Aldrich.
  • the amine is present in the reactants of polyurethane polymer from 1 to 20 wt.%, preferably 1.5 to 8 wt.%, based on the total weight of the reactants of the polyurethane polymer. If the amount of amine is lower than the range, the bonding strength of the cured adhesive may not be sufficient to use for flexible packaging application.
  • the mixture of isocyanate-reactive compounds may contain other isocyanate-reactive compounds such as other polyols and/or other amines if the adhesion properties and debonding effect of the adhesive still can be achieved.
  • the mixture of isocyanate-reactive compounds may contain less than 10% by weight, or less than 5% by weight, or less than 1% by weight of polyester polyol, and preferably essentially contains no, and more preferably contains no polyester polyol.
  • the mixture of isocyanate-reactive compounds may contain less than 1% by weight, or less than 0.5% by weight of N-butyldiethanolamine and/or diethanolamine.
  • the mixture of isocyanate-reactive compounds essentially comprises no N-butyldiethanolamine and/or diethanolamine, and more preferably comprise no N-butyldiethanolamine and/or diethanolamine.
  • the adhesive composition according to the present invention is organic solvent based, and contains an organic solvent.
  • organic solvents include heterocyclic, aliphatic, or aromatic hydrocarbons such as toluene, isophorone, xylene, mono- or polyhydric alcohols such as ethylhexanol, butoxypropanol, isopropanol, butyl diglycol, methanol, ethanol, propanol, and butanol, ethers such as diethylene glycol dimethyl ether and dipropylene glycol methyl ether, ethyl glycol and butyl glycol, esters such as ethyl acetate, butyl acetate, pentyl acetate, or ethyl ethoxypropionate, ketones such as cyclohexanone, methyl ethyl ketone (MEK), methyl amyl ketone, methyl isobutyl ketone (MIBK), and acetone,
  • the organic solvent is present in the adhesive composition in an amount of 5 to 80% by weight, preferably 10 to 70% by weight of the total weight of the adhesive composition.
  • the adhesive composition according to the present invention is thus organic solvent-based. Water may be contained in the adhesive composition if it is compatible with the organic solvent, but the amount of water is limited.
  • the adhesive composition comprises essentially no water, preferably comprises no more than 5 wt%, more preferably no more than 1 wt%, and in particular no more than 0.5 wt% of water based on the total weight of the adhesive composition. In one preferred embodiment, the adhesive composition comprises no water.
  • composition according to the invention may further comprise additives.
  • additives may be used to affect the properties of the composition, for example the mechanical properties and debonding effect.
  • the one or more additives are selected from the group consisting of catalysts, fillers, pigments, rheology modifiers, drying agents, flame retardants, curing agents, adhesion promoters, surface active agents and anti-foaming agents.
  • Examples of the catalyst include tertiary amine compounds and organometallic compounds.
  • tertiary amine compound examples include triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine, diazabicycloundecene (also known as DBU), and the like.
  • organometallic compound examples include a tin compound and a non-tin compound.
  • tin compound examples include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, Examples include tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate.
  • non-tin compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride, lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate, iron compounds such as iron ethylhexanoate and iron 2,4-pentadionate, cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate, zinc compounds such as zinc naphthenate and zinc 2-ethylhexanoate and zirconium naphthenate.
  • titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride
  • lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate
  • iron compounds such as iron
  • DBU diazabicycloundecene
  • DBTDL dibutyltin dilaurate
  • zinc 2-ethylhexanoate and the like are preferable in terms of reactivity.
  • the catalyst can be used alone or in combination of two or more.
  • the NCO/OH ratio of the polyisocyanate, the mixture of isocyanate-reactive compounds, and optional NCO-containing curing agent is the range of 0.8 to 1.2.
  • the polyurethane polymer usually has an NCO content of from 0 to 5 wt.% (determined according to Spielberger, DIN EN ISO 11909:2007-05).
  • the preparation of the polyurethane polymer is known in the art, and may comprise the steps of (1) mixing the polyether polyol and optional additives in an organic solvent to homogeneity; (2) adding polyisocyanate and optional NCO-containing curing agent to react with the polyether polyol at 50°C to 80°C under stirring; (3) obtaining the polyurethane polymer.
  • the preparation of the solvent-based adhesive composition may comprise the steps of adding additional organic solvent in the polyurethane polymer to reach a solid content of 30 to 80% by weight.
  • the adhesive composition may consist of one-component or multi-components.
  • the adhesive composition is two-component composition consisting of a resin component, a curing component and an organic solvent.
  • the resin component comprises a polyurethane polymer obtainable by the reactants comprising,
  • the curing component comprises a curing agent which can react with the excess functional groups of the polyurethan polymer (prepolymer).
  • the curing agent can be those used for the aliphatic polyisocyanates and alicyclic polyisocyanates.
  • the curing agent hexamethylene diisocyanate (HDI) or derivatives thereof, such as HDI biuret (commercially available, for example, as Desmodur N3200), HDI trimer (commercially available as Desmodur N3300) or dicyclohexylmethane diisocyanate (commercially available as Desmodur W).
  • the adhesive composition of the present invention may comprise an adhesion promoter to increase the adhesion strength of the cured adhesive.
  • Adhesion promoters which may be present are the adhesion promoters known from the prior art, in particular aminosilanes, in the composition according to the invention.
  • an adhesion promoter may preferably alkoxysilyl group-bearing compounds which additionally have primary or secondary amino groups, vinyl groups, thiol groups, aryl groups, or alternatively oxirane groups such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(n-butyl) aminopropyltrimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-glycidyloxy-propyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, phenyltrimethoxysilane or oligomeric amino / alkyl-alkoxysilanes, each used alone or in admixture.
  • the present invention is also directed to the cured adhesive obtainable by curing an adhesive composition according to the present invention.
  • the inventors have found that the adhesive compositions of the present invention exhibit excellent adhesive strength on substrates for flexible packaging, meanwhile possess debonding property when treated under mild conditions such as under water or aqueous solution such as water/ethanol solution at atmospheric conditions.
  • the cured adhesive has a bonding strength on a polyethylene substrate of no less than 1 N/15mm, and preferably no less than 1.5 N/15mm measured according to DIN 53357.
  • the cured adhesive on a polyethylene substrate is soluble or dispensable in water or an aqueous solution such as an aqueous solution containing ethanol (water/ethanol solution) under atmospheric conditions.
  • the present invention is directed to a flexible packaging material comprising a first layer comprised of a first polyolefin or first polyester; a second layer comprised of a second polyolefin, which may be the same or different from the first polyolefin, a second polyester, which may be the same as or different from the first polyester, or a metal foil; and cured adhesive of the present invention bonding the first layer to the second layer.
  • the present invention is directed to a method of making a flexible film laminate, comprising: combining the components of polyurethane adhesive system according to the present invention at a predetermined weight ratio to form an adhesive mixture; disposing the adhesive mixture on at least a portion of one surface of a first flexible film, joining the first flexible film and a second flexible film wherein the adhesive mixture is interposed between the first flexible film and the second flexible film; and curing the adhesive mixture.
  • the film or films to be coated and adhered to each other using the adhesive compositions may be comprised of any of the materials known in the art to be suitable for use in flexible packaging, including both polymeric and metallic materials as well as paper (including treated or coated paper).
  • Thermoplastics are particularly preferred for use as at least one of the layers.
  • the materials chosen for individual layers in a laminate are selected to achieve specific desired combinations of properties, e.g., mechanical strength, tear resistance, elongation, puncture resistance, flexibility/stiffness, gas and water vapor permeability, oil and grease permeability, heat sealability, adhesiveness, optical properties (e.g., clear, translucent, opaque), formability, merchantability and relative cost.
  • Individual layers may be pure polymers or blends of different polymers.
  • the polymeric layers are often formulated with colorants, anti-slip, anti-block, and anti-static processing aids, plasticizers, lubricants, fillers, stabilizers and the like to enhance certain layer characteristics.
  • Particularly preferred polymers for use include, but not limited to, polyethylene (including low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HPDE), high molecular weight, high density polyethylene (HMW-HDPE), linear low density polyethylene (LLDPE), linear medium density polyethylene (LMPE)), polypropylene (PP), oriented polypropylene, polyesters such as poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT), ethylene-vinyl acetate copolymers (EVA), ethylene-acrylic acid copolymers (EAA), ethylene-methyl methacrylate copolymers (EMA), ethylene-methacrylic acid salts (ionomers), hydrolyzed ethylene-vinyl acetate copolymers (EVOH), polyamides (nylon), polyvinyl chloride (PVC), poly(vinylidene chloride) copolymers (PVDC), polybutylene, ethylene-prop
  • the polymer surface may be treated or coated, if so desired.
  • a film of polymer may be metallized by depositing a thin metal vapor such as aluminum onto the film's surface. Metallization may enhance the barrier properties of the finished laminate.
  • the polymer film surface may also be coated with anti-fog additive or the like or subjected to a pretreatment with electrical or corona discharges, or ozone or other chemical agents to increase its adhesive receptivity.
  • a coating of an inorganic oxide such as SiOx or AlOx may also be present on the polymer surface (for example, an SiOx- or AlOx-coated PET film).
  • One or more layers of the laminate may also comprise a metal film or foil, such as aluminum foil, or the like.
  • the metal foil will preferably have a thickness of about 5 to 100 ⁇ m.
  • the individual films comprising the laminates can be prepared in widely varying thicknesses, for example, from about 5 to about 200 microns.
  • the films, foils, and laminating adhesive composition can be assembled into the laminate by using any one or more of the several conventional procedures known in the art for such purpose.
  • the adhesive formulation may be applied to the surface of one or both of two films/foils by means of extrusion, brushes, rollers, blades, spraying or the like and the film/foil surfaces bearing the adhesive composition brought together and passed through a set of rollers (often referred to as nip rollers) which press together the film/foils having the adhesive composition between the films/foils.
  • the resulting laminate may be rolled or wound onto a reel for ageing.
  • the adhesive may be applied by conventional techniques; e.g., a 3/4-roller coating mechanism in the case of the use of a solvent-free system, or a 2-roller coating mechanism in the case of the use of a solvent-containing system.
  • the coating weight at which the adhesive formulation can be applied to the surface of a film layer is in the range of about 0.1 to about 10 g/m 2 , and more typically about 2.0 to about 6.0 g/m 2 .
  • the adhesive compositions are believed to be largely chemically cured through the evaporation of the organic solvent, or the reaction of the formulation constituents containing isocyanate groups and the constituents containing hydroxyl or other active hydrogen groups.
  • curing can also be accomplished at least in part through moisture curing. Although sufficient moisture may be inherently present on the film or foil surfaces for this purpose, water may also be deliberately introduced through conventional methods if so desired.
  • Laminates prepared in accordance with the present disclosure may be used for packaging purposes in the same manner as conventional or known flexible laminated packaging films.
  • the laminates are particularly suitable for forming into flexible pouch-shaped container vessels capable of being filed with a foodstuff and sealed.
  • two rectangular or square sheets of the laminate may be piled in the desired configuration or arrangement; preferably, the two layers of the two sheets which face each other are capable of being heat-sealed to each other.
  • Three peripheral portions of the piled assembly are then heat-sealed to form the pouch. Heat-sealing can easily be accomplished by means of a heating bar, heating knife, heating wire, impulse sealer, ultrasonic sealer, or induction heating sealer.
  • FIG. 1 shows a sectional view of a food packaging film 10.
  • This food packaging film 10 is a laminate comprising one metal foil 14 and two plastic films 12 and 13, and the plastic films 12 and 13 are adhered on both sides of the metal foil 14 by using adhesive layers 11, respectively.
  • the plastic film 12 is preferably, for example, a polyethylene terephthalate (PET) film
  • the film 13 is preferably a polyolefin film, more preferably a PE film.
  • the metal foil 14 is inserted between them.
  • the metal foil 14 may be, for example, an aluminum foil.
  • the film 12 is bonded to the metal foil 14, and the film 13 is bonded to the metal foil 14 by the adhesive layers 11 for food packaging films, respectively.
  • the film to be laminated include plastic films produced from polyethylene terephthalates, nylons, polyethylenes, polypropylenes, and polyvinyl chlorides; metal foils such as aluminum foil; deposited films such as metal deposited films and silica deposited films; metal films produced from stainless steel, steel, copper, and lead.
  • the thickness of the film to be laminated, for example, plastic film is preferably within a range of 5 to 200 ⁇ m.
  • the present invention also relates to a method of recycling a flexible packaging material comprising,
  • the treating agent is preferably water as no additional washing step is necessary for cycling the flexible packaging material.
  • the appearance of the polyurethane reaction product was visually observed if it was liquid, viscous liquid or gel when the batch product was cooled to at least 50°C.
  • the reaction speed of producing the polyurethane was evaluated as good if the synthesis was completed within 24 hours. Otherwise, it would be evaluated as poor.
  • the polyurethane reaction products were kept in a water bath at 20°C before the viscosity measurement started.
  • Brookfield Viscosimeter DV-II Pro Extra was used for the measurement to ensure that the torque of the device was between 20% to 80%.
  • the produced adhesive was diluted in ethyl acetate or ethanol to lower the viscosity in order to ensure a proper spreading of the adhesive on the foils.
  • the solubility was evaluated as good if the adhesive could be easily dissolved in the solvent. If a phase separation in the solvent was occurred, it would be evaluated as poor.
  • a prepared carrier foil e.g. aluminium foil; DIN A4 size
  • a scraper was placed on top of the foil. Below the scraper, a couple of drops of each adhesive compositions in the examples were added.
  • the scraper was pulled from the top of the foil to the bottom of it. Then the solvent was evaporated in an oven for 5 minutes at 90°C. After the evaporation the foil was cooled down for several seconds before the foils was placed on a laminator where the second foil was laminated against the carrier foil.
  • a pressure of 4 bar a lamination speed of 10 m/min and a roller temperature of 60°C were used to produce a laminate sample.
  • the laminates were cut in stripes with a defined width of 15 mm. A therefore prepared sample cutter was used to maintain the same width for all samples. The sample was separated on one side, afterwards the sample was clamped into a Zwick or Instron testing machine and the force for the separation of both foils was measured.
  • the two-component adhesive composition consists of a polyurethane resin component and a curing component.
  • the polyurethane resin component was prepared as follows. In a 250 mL three neck flask with a stirrer, thermometer and a cooler, 32.58 parts by weight of PEG 400, 3.24 parts by weight of MDEA and 81.49 parts by weight of ethyl acetate were added to the flask. After stirring until the mixture became homogeneous, 48.54 parts by weight of IPDI were added. The reaction was carried out at 70°C with a stirring speed of 200 rpm. To determine the completion of the reaction, FTIR (Perkin Elmer Spectrum Two) measurements were made. The reaction was regarded as complete, if no - NCO group signal (at about 2265 cm -1 ) could be observed in the FTIR spectrum. If the reaction was completed, the batch was cooled to at least 50°C before the batch was filled into proper glass container for storage.
  • the curing component is a mixture of HDI-biuret (52.2 parts by weight), bis-AMEO (27.8 parts by weight) and ethyl acetate (20 parts by weight).
  • the resin component and the curing component were then mixed in a weight ratio of 16:1.
  • the produced laminates needed to cure at 40°C due to the excess of isocyanates in the two-component adhesive system. After a standard curing time of 14 days, the samples for debonding property were prepared.
  • the debonding of the 2K adhesive was achieved in a water/ethanol mixture (1:1) in 24 hours.
  • the other properties of the adhesive were good or fulfil the needs.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Adhesives Or Adhesive Processes (AREA)
EP22153603.0A 2022-01-27 2022-01-27 Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien Pending EP4219580A1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP22153603.0A EP4219580A1 (de) 2022-01-27 2022-01-27 Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien
PCT/EP2023/050038 WO2023143876A1 (en) 2022-01-27 2023-01-03 Solvent-based polyurethane adhesive composition for bonding flexible packaging material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22153603.0A EP4219580A1 (de) 2022-01-27 2022-01-27 Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien

Publications (1)

Publication Number Publication Date
EP4219580A1 true EP4219580A1 (de) 2023-08-02

Family

ID=80121893

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22153603.0A Pending EP4219580A1 (de) 2022-01-27 2022-01-27 Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien

Country Status (2)

Country Link
EP (1) EP4219580A1 (de)
WO (1) WO2023143876A1 (de)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3887757A (en) * 1973-05-29 1975-06-03 Inmont Corp Laminates having a polyurethane adhesive
US3887755A (en) * 1973-09-11 1975-06-03 Inmont Corp Laminating adhesives
US3932561A (en) * 1973-09-11 1976-01-13 Inmont Corporation Adhesives comprising solutions of a mixture of a terpene urethane resin with thermoplastic polyether polyurethanes containing tertiary amine group
US3982986A (en) * 1973-05-29 1976-09-28 Inmont Corporation Laminates and method of making them
JPS60212455A (ja) * 1984-04-09 1985-10-24 Toho Chem Ind Co Ltd 水系樹脂の製法
EP0443537A2 (de) * 1990-02-20 1991-08-28 Takeda Chemical Industries, Ltd. Wasserlösliche photovernetzbare Polyurethanpoly(meth-)acrylate, diese enthaltende Klebstoffe und Herstellung von laminierten Produkten
EP1146061A1 (de) * 1999-08-30 2001-10-17 Toyo Ink Manufacturing Co. Ltd. Urethan-harnstoff-harz durch michael-addition, verfahren zur herstellung desselben, haftkleber, verfahren zur herstellung desselben, beschichtungsmaterial zum herstellen einer tintenabsorbierenden schicht und aufnahmegerät
US6870006B2 (en) 2003-05-19 2005-03-22 Henkel Kommanditgesellschaft Auf Aktien (Henkel Kgaa) Water-soluble hotmelt adhesive
KR20050120121A (ko) * 2004-06-18 2005-12-22 한서포리머주식회사 핫멜트 폴리우레탄계 접착제
CN106893543A (zh) * 2017-04-27 2017-06-27 福州皇家地坪有限公司 一种预制型柔性磨石系统
KR101874301B1 (ko) * 2017-01-02 2018-07-04 (주)노루페인트 핫멜트 접착제용 폴리우레탄 수지 및 이를 포함하는 2액형 폴리우레탄 핫멜트 접착제 및 핫멜트 접착제용 폴리우레탄 수지의 제조방법.

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3887757A (en) * 1973-05-29 1975-06-03 Inmont Corp Laminates having a polyurethane adhesive
US3982986A (en) * 1973-05-29 1976-09-28 Inmont Corporation Laminates and method of making them
US3887755A (en) * 1973-09-11 1975-06-03 Inmont Corp Laminating adhesives
US3932561A (en) * 1973-09-11 1976-01-13 Inmont Corporation Adhesives comprising solutions of a mixture of a terpene urethane resin with thermoplastic polyether polyurethanes containing tertiary amine group
JPS60212455A (ja) * 1984-04-09 1985-10-24 Toho Chem Ind Co Ltd 水系樹脂の製法
EP0443537A2 (de) * 1990-02-20 1991-08-28 Takeda Chemical Industries, Ltd. Wasserlösliche photovernetzbare Polyurethanpoly(meth-)acrylate, diese enthaltende Klebstoffe und Herstellung von laminierten Produkten
EP1146061A1 (de) * 1999-08-30 2001-10-17 Toyo Ink Manufacturing Co. Ltd. Urethan-harnstoff-harz durch michael-addition, verfahren zur herstellung desselben, haftkleber, verfahren zur herstellung desselben, beschichtungsmaterial zum herstellen einer tintenabsorbierenden schicht und aufnahmegerät
US6870006B2 (en) 2003-05-19 2005-03-22 Henkel Kommanditgesellschaft Auf Aktien (Henkel Kgaa) Water-soluble hotmelt adhesive
KR20050120121A (ko) * 2004-06-18 2005-12-22 한서포리머주식회사 핫멜트 폴리우레탄계 접착제
KR101874301B1 (ko) * 2017-01-02 2018-07-04 (주)노루페인트 핫멜트 접착제용 폴리우레탄 수지 및 이를 포함하는 2액형 폴리우레탄 핫멜트 접착제 및 핫멜트 접착제용 폴리우레탄 수지의 제조방법.
CN106893543A (zh) * 2017-04-27 2017-06-27 福州皇家地坪有限公司 一种预制型柔性磨石系统

Also Published As

Publication number Publication date
WO2023143876A1 (en) 2023-08-03

Similar Documents

Publication Publication Date Title
US11702572B2 (en) Two-component solventless adhesive compositions
EP3574031B1 (de) Lösemittelfreie zweikomponentenklebstoffzusammensetzung
US20210198539A1 (en) Two-component solventless adhesive compositions comprising an amine-initiated polyol
EP3455274B1 (de) Zweikomponentige lösemittelfreie klebstoffzusammensetzungen mit einem amininitiierten polyol
CN114921215A (zh) 不含聚酯的层合粘合剂组合物
US9657206B2 (en) Adhesive formulations
CN109476974A (zh) 基于聚氨酯的粘合剂双组分组合物
CN109642142A (zh) 基于聚氨酯的粘合剂双组分组合物
US11312888B2 (en) Two-component solventless adhesive compositions and methods of making same
EP3328910A1 (de) Aminobenzoat-terminierte materialien für laminierte klebstoffe
EP4219580A1 (de) Polyurethanklebstoffzusammensetzung auf lösungsmittelbasis zum verkleben von flexiblen verpackungsmaterialien
EP3630862A1 (de) Lösemittelhaltige klebstoffzusammensetzungen
WO2024016319A1 (en) Solvent-free polyurethane adhesive composition and use thereof
TWI839322B (zh) 雙組分無溶劑黏著劑組合物及製造其之方法
EP4370570A1 (de) Zweikomponentige polyurethanklebstoffzusammensetzung zur folienlaminierung in einer heissabfüllanwendung
EP4370569A1 (de) Zweikomponenten-polyurethanklebstoffzusammensetzung mit einer ethoxysilanfunktionalisierten isocyanatverbindung zur folienlaminierung
EP4370568A1 (de) Zweikomponenten-polyurethanklebstoffzusammensetzung für folienlaminierung
WO2023284976A1 (en) Polyurethane adhesive composition for film lamination
TW202102573A (zh) 基於水之組合物

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20240201

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR